Grinding machine



July 26, 1938. A. o. SCHAEFER v 2,124,593

' GRINDING MACHINE 7 Filed Jan. 8, 1937 3 Sheets-Sheet l i K\ I $1 N k 5%402 aacfigf ATTORNEY.

' July 26, 1938. Q SCHAEFER 2,124,593

GRINDING MACHINE Filed Jan. 8, 1937 3 Sheets-Sheet 2 IN VENTOR.

B $140.; A aey er ATTORNEY.

July 26, 1938. A. o. SCHAEFER GRINDING MACHINE Filed Jan. 8, 1957 3 Sheets- Shed. 3

mm m 5 5 w Patented July 26, 1938 UNITED STATES GRINDING MACHINE Adolph 0. Sohaefer, Brooklyn,

Company,

Atlantic Service N. Y., assignor to Ind, Brooklyn,

N. Y., a corporation of New York 1 Application January 8,

Claims.

This invention relates to grinding machines and is adapted for grinding edged tools. An object of the invention is to provide an abrasive belt for grinding the tool with a tool holder adjustably 5v positioned relative to the belt. Another object of the invention is to provide a pair of abrasive belts angularly disposed relative to each other with a tool holder for positioning the tool in the grinding position for each belt. Another object of the invention is to provide an enclosed frame or housing for the abrasive belt, pivotally mounted on a sleeve which forms the bearing for the mechanism operating the abrasive belt. Other objects of the invention will be more particularly l5: understood from the following specification and from the accompanying drawings, selected to show one form of the invention, and in which Fig. 1 is a front elevation of the grinding machine complete;

Fig. 2 is a rear elevation of the machine with the driving motor removed;

Fig. 3 is a sectional elevation on line 3--3, Fig. 2;

Fig. 4 is a top plan view of the tool holder;

Fig. 5 is an end view from the rear of the tool holder;

Fig. 6 is an end view from the front of the tool holder, and

Fig. '7 is a diagram showing the relation of the 30'. tool holder, the tools, and the grinding belts;

This application relates to the same type of machine as my co-pending application 92,272, filed July 24, 1936, for Tool grinders. It comprises a base supporting a motor with a drive 35; mechanism and a vertical bearing plate against which the enclosed frames of the abrasivebelts are pivotally mounted so that the angular position of the belts may be adjusted. A tool holder is provided between the frames and opposite an 40 exposed portion of the abrasive belts. This hold; er is adjustably clamped to the bearing plate so that its elevation can be adjusted to suit the angular position of the belts. The tool holder comprises a triangular shaped member located 45 between the frames, having a head at one end by which it is secured to the bearing plate. This member is provided with a vertical slot opposite each of the abrasive belts. The knife or tool to be ground is inserted in the slot until it engages 50 the abrasive belt which grinds it on one side and then it is transferred to the opposite slot where the opposite abrasive belt grinds it on the other side. The central member of the tool holder is recessed or tapered to an edge opposite the belts 55 so as to provide ample clearance for the belts.

1931, Serial No. 119,547

The central member of the tool holder is provided with parallel sides at the front and at the back so that the tool is held vertical during the grinding operation. The front end of the tool holder is provided with a removable plate which forms the parallel sides of the central member and against which the tool bears in operation.

In the drawings, II is the base which supports the motor I5 and the pad I2 upon which the bearing member 22 and the drive mechanism cover 23 is mounted. The frame I3 is pivoted to the bearing plate 22 on the-axis 26 and the frame I4 'ispivoted in the same Way, on the axis 29. The'frames I3 and I4 are provided with an enclosing cover 10 secured by nut I3 on the stem 69-. The tool holder is indicated at 26, Fig. 1, located between frames I3 and I4 and an index member-1s provided at I8 on the pad I2 with registering index marks 0 on I3 and I4 whereby the angular position of bothframes may be adjusted to correspond with each other.

The frame I' l, Fig. 3,- is mounted against the vertical'plate 22 on the sleeve bearing 62 which has a flange at 63 and is mounted in an aperture in the gear housing 23' and is secured in place by the stud bolts 64. The plate 22 is provided with an arcuate slot at 25 with a stud engaging the clamping nut 2'I whereby the frame is clamped in" the position desired after it is adjusted on the bearing 62. Theframe is provided with an idler roller6l, mounted'on shaft 68 and supported by arm' 30 on the bolt13I. The arm 35 has a free vertical movement inwhich 68 moves in slot 33 'and aspring 34'is'provi'ded to normally raise the arm.- This armmay-b elowered and latched in the lower position by the cam 3'! pivoted at 36 to the arm 30'andarrange d to engage the stop 35 when'the handle 38-is moved upwards. The frames I3 and I4 are provided with similar mechanisms, the corresponding parts being distinguished by a prime mark, and the slot 28 corresponds with the slot 25.

The motor shaft is connected through the coupler I6, H, with the drive shaft 52, carrying the spiral gear 53, Fig. 3, engaging the spiral gear 54, secured to shaft 55 by nut 56 and running in the sleeve bearing 62 and the end bearing 26. The belt wheel 58 is mounted at 51 on a reduced section of shaft 55 and is secured in place by the nut 59. A drive pin 60 projects from shaft 55 and engages the recess'BI on the face of pulley 58, thereby insuring a positive drive for this pulley from the driving shaft 52. The pulley 58 is provided with a rubber tire 66, preferably of comparatively soft rubber to provide the adhesion I3 and [4, the end bearings of which are indicated at 26 and 29, the construction being similar to that in Fig. 3. The mechanism is made in two separate parts which are. divisible on the centre line of shaft 52 as indicated by the line between the parts I! and 23.

The tool holder is preferably made from a single casting having a central member 15 and two outside members 76 and 11, forming the vertical slots 82 and 83 to receive the tool. The device is provided with a head at the attaching end comprising the wings 18 and 19, provided with the slots 84 and 85 which clamp against the plate 22 by the clamping screws 8'! an d 88. Pads are formed in the casting at 88 to strengthen the side members of the tool holder where they attach to the central member below the slots. The

central member is tapered as indicated at 86 towards the apex of the belts so that the contour of this member, with the outer faces of 16 and '51, form a triangular structure which is intercepted by the vertical slots 82 and 83. The abrasive belts move opposite the tool holder and between the positions indicated by lines (1 and e.

Fig. 4.

edge engages the abrasive belt 1| and in this po- The tool a Fig. 7, is inserted in slot 82 until the sition the" tool is moved back and forth during the grinding operation. After one side is ground in this way the tool is transferred to slot 83 as indicated at b and the oppositeside is engaged by the abrasive belt 14 running onthe idler pul ley 13. Y

It will be noted that the pressure between the grinding edgeand the abrasive belt is taken up by the central member 15 of the tool holder and in order that the tool may not be defiectedfrom its position where the central member is recessed at 86, the slots 82 and 83, Fig. 5, are parallel and the other end of the central member 15 is provided with a plate 8|, secured thereto by screws whose sides are parallel and correspond with the central member at the opposite end. This holds the blade rigid and vertical during the grinding operation and in the same position with respect to both belts.- The plate BI is made detachable so that'it may be easilyreplaced asit' wears away, and so that it 'may be made of harder material than the tool holder itself. 7 e This invention admits 'of-applications other than those shown and which are fully contemplated in the appended claims.

Having thus described my invention, I claim: 8 1. A tool holder for holding a tool to agrinding belt'comprising an integral member extending across the face of the belt and having a slot therein engaging both sides of the tool in the grinding position, and providing for the free transverse movement of the tool said member having wings at one end as the only means for slot being angularly disposed with reference to the belt, said member having a head at one end by whichit is adjustably secured with reference to the belt and having a removable plate at the opposite end outside the plane of thebelt conforming to' the side of the slot opposite the belt.

3. A tool holder for holding tools to a-pair of angularly disposed grinding belts comprising an integral member extending across the face of the belts and angularly shaped to conform to the position of the belts, and having a vertical slot for the tool opposite each belt said slots being parallel and extending through said holder and 'engaging both sides of the tool in the grinding position and providing for the free transverse movement of the tool, the central member of said holder being "recessed opposite said belts to clear the belts and means conforming to the wall of the slots. for rigidly supporting the tool againstthe belts at the ends of the holder.

4; A machine for grinding knives and the like comprising, a base having a gear box and a single vertical plate, a pair of frames each having a pair of-v rollers and an abrasive belt mounted on each pair of rollers, ,.said frames being placed against said plateand solely supported thereby, a driving shaft mounted inthe base having a pair of spiral gears, a drive shaft for one of each pair of rollers, each having a spiral gear engaging one of the spiral gears of the driveshaft to drive the belts, a sleevebearing with a flange for ing apertures in the frame-and in the plate withgi the flange engaging the frame to hold it, against the plate and clampingthe frame to the plate to pivot about the axis of the roller, an arcuate slot insaid vertical plate and a stud in said slot for clamping the frame in position plate. V

5. A machine for grinding knives and the like comprising a base with a motor thereon, a hori-. Zontal shaft withspiral gears driven by said mo tor, a removable cover for said base enclosing said gears and having. a vertical plate thereon, a pair of frames pivotally. mounted against said plate and solely supported thereby, an abrasive belt in each frame, a drive roller for each belt;v a shaft for each drive roller extending into the cover at right angles to the horizontal shaft and having; a gear engaging one of the gears on the. horizontal against said:

ADOLPH 0. SCHAEFERf 

